//non numeric input yerminates loop
#include<iostream>
const int Max = 5;
int main()
{
    using namespace std;
    //get data
    double fish [Max];
    cout<< "Please enter the wweights of your fish.\n";
    cout << "You may enter up to "<<Max<< " fish <q to terminate>.\n";
    cout << "fish #1: ";
    int i = 0;
    while (i<Max && cin >> fish[i]){
        if(++i <Max)
            cout << "fish #"<<i+1<< ": ";
    }
    //计算平均值
    double total = 0.0;
    for (int j =0 ; j<i;j++)
        total += fish[j];

    //汇报最后统计的结果
    if(i == 0)
        cout << "No fish\n";
    else
        cout << total /i << " = average weight of "<< i << " fish\n";
    cout << "Done.\n";
    return 0;
}
